Emotions ran high Sunday afternoon during a panel discussion held in response to complaints about a paucity of Asian actors in La Jolla Playhouse’s musical “The Nightingale,” a Page to Stage production based on the Hans Christian Andersen fable set in China.

Actor and playwright Christine Toy Johnson, a panelist who flew in from New York to see the production, praised set designers for creating an authentic Chinese atmosphere, but she said the lack of Asian-American faces felt like “a knife to the heart” and reminded her “how invisible we still are.”

Actor and fellow panelist Cindy Cheung, a member of the Asian-American Performers Action Coalition, expressed “disgust” and “confusion” with the casting, noting that an earlier version of the work had an all-Asian cast.

“I’m still kind of getting over the shock of it,” she said. “Seeing so many people being OK with this is very disturbing.”

The Playhouse’s artistic director, Christopher Ashley, and director Moisés Kaufman both offered an apology for what they said could be construed as a glaring omission, adding that their casting was never intended to offend the Asian-American community or fellow artists.

Kaufman, who also wrote and directed “The Laramie Project,” said he has devoted most of his professional life to giving voice to the lesbian, gay, bisexual and transgender community. He said the La Jolla Playhouse has consistently engaged the public in social justice issues through its works.

“Usually, we are the ones screaming for representation … for inclusion, that minority groups are not properly represented on American stages,” he said.

Kaufman maintained that the creative team’s emphasis was less on historical and cultural accuracy than on Andersen’s mythical aspects, which include a talking bird and a Chinese palace made of porcelain.

Kaufman said they strove to assemble a cast that included as many ethnicities “as populate the American landscape.”

“We were never interested in setting it in a real China … at a real moment in time,” he said. “Otherwise, our casting choices would have been very different.”

Though the set includes Chinese lanterns and other accurate vestiges of Chinese culture, it also includes Moroccan lanterns and an emperor’s robe based on that of an Iranian emperor, he said.

However, Kaufman conceded that his team was largely “unsuccessful in articulating what we were trying to do.”

“We owe everybody an apology,” he said.

If the Playhouse wanted to populate the stage with as many multiethnic backgrounds as possible, Cheung questioned, why was the cast still 50 percent Caucasian?

“It’s so glaring that there are no Asian-American men on the stage, except for the puppets, and even then we’re not sure,” she quipped. “They could have been Moroccan.”

Panelist Andy Lowe, former producing artistic director of the San Diego Asian-American Repertory Theatre, questioned whether the audience had the “cultural context” to discern the multicultural set details.

Johnson expressed her respect for the current cast, but she noted that the names of the characters are all still Chinese.

“That’s a big disconnect,” she said. “Multicultural casting was never meant to justify a Caucasian person playing a culturally specific role.”